The inventive concept relates generally to non-volatile memory devices. More particularly, the inventive concept relates to non-volatile memory devices driving dummy word lines corresponding to different memory cell strings and a method of operating such non-volatile memory devices.
Non-volatile memory devices retain stored data in the absence of applied power while at the same time efficiently allowing data to be electrically programmed and erased. Flash memory is one type of commonly used non-volatile memory device.
NAND type flash memory is characterized by an arrangement of memory transistors associated with memory cells into so-called NAND strings. In this type of arrangement, word lines orthogonally traverse the NAND strings and are respectively coupled to one or more memory transistors in each NAND string. While this arrangement of NAND strings and associated word lines is geometrically and operationally efficient, the inadvertent programming (i.e., errant alteration) of stored data in proximate, albeit unselected, NAND strings is a problem.
Numerous attempts have been made to remediate this potential problem. For example, International Patent Publication Nos. WO05/078733 and WO06/124525 disclose one technique for preventing the inadvertent programming of data stored in unselected NAND strings by using channel boosting. Channel boosting may reduce a program potential applied to memory transistors by applying a high boosting voltage to channels of unselected NAND strings.